Automatic door lock



Mweh M, 3967 H. NEVELING AUTOMATIC DOOR LUCK 2 Sheets-Sheet 1 FiledSept. 22, 1964 lNVE/VTOF IL/ 1? W/G N5 VEL m/c g/u WM 2 Sheets-Sheet 2Filed Sept. 22, 1964 0 J a 01 u.

HEZfn/IG A/E VEL ING United States Patent 3,309,125 AUTOMATIC DOOR LOCKHerwig Neveiing, 148 Honnetalstrasse, Deilinghofen, Westphalia, GermanyFiled Sept. 22, 1964, Ser. No. 398,314 1 Claim. (Cl. 292-78) Thisinvention relates to an automatic door lock in which the latch isoperated by a rectilinearly guided energy storage means, which iscoupled with a damping piston, through the intermediary of a gear withbeyonddead center position.

In the known door locks of this kind, the lever-type latch is coupledwith a spring serving as an energy storage means, through theintermediary of a lever system. In the unlocking position of the latch,the spring is compressed. Since, however, the transmission rods are in abeyond-dead center position, the spring is not capable of pivoting thelatch into its locking position. When the door is being closed, thelatch strikes against the locking plate, where-by the beyond-dead-centerposition is overcome so that the spring can move the latch into itslocking position with the door being pulled into the doorframe. Thelocking is clamped by the action of a damping piston.

In a known automatic door lock of this type, the latch is secured to anangle lever which is coupled with the energy storage means through theintermediary of a con necting rod. In this arrangement, the arm of theangle lever which is hinged to the connecting rod must have a lengthsufllcient to securely reach the beyond-dead center position. Moreover,a sufficient length of this lever arm is also required to ensure thatthe door is pulled shut as smoothly as possible. Consequently, theinstallation of such a door lock in relatively thin door edges is veryditficult. The numerous bearings of the rod guide involve considerablewear. Finally, the accurate installation of this door lock requires anexceptionally high skill, since even the slightest tilting Will besufficient to cause the latch to strike the locking plate in a one-sidedmanner, which will result in deformations of the lever system and damageof the door lock.

Another known door lock, which, however, lacks an energy storage means,has a complicated lever system including an arm-rocker lever and aplurality of guide rods so that this door lock is still more subject tothe above-mentioned difficulties.

Also, a door lock for heavy doors such as stove-doors is known in whicha fork-like latch bears with a cam against a spring-biased plate. Whenthe door is being closed or pulled open, the latch is shifted and movedinto the respective end position by the spring-biased plate. This lockhas no damping means so that it works rather roughly. Consequently, itis not suited for normal doors in which the closing movement is to bedamped by the door lock.

It is the object of the present invention to avoid the disadvantages ofthe known door locks and to provide a simply constructed automatic doorlock in which hinge connections or moving joints are possiblyeliminated.

To attain this object, the invention provides an automatic door lock inwhich the latch is operated by a rectilinearly guided energy storagemeans, which is coupled with a damping piston, through the intermediaryof a gear with beyond-dead center position, which is characterized inthat the rod of the energy storage means mounts a rectilinearly guidedsliding member of a cam drive, the cam means of the cam drive, which isguided within the sliding member, and the latch being rigidly'mounted ona common pivot.

Preferably, the cam means is an eccentric disc positively seated withinthe sliding member.

The door lock proposed by the present invention therefore uses only onebearing for the pivot mounting the latch and the eccentric disc.Moreover, only straight or rectilinear slide guides are used so that thelock can be realized with very small dimensions. This feature enablesthe door lock proposed by the invention to be incorporated in all kindsof doors such as wooden doors or steel doors as well as doors with orwithout a rebate. If the latch is ununiformly loaded due to improperinstallation of the lock, the resulting forces can be absorbed by thebearing of the pivot without any transmission of torsional forces toother components of the door lock.

A preferred embodiment of the invention will now be described by way ofexample and with reference to the accompanying drawings, in which:

FIG. 1 is a side elevational view of an automatic door lock according tothe invention;

FIG. 2 is a longitudinal section through the lock viewed in thedirection of the attachment plate, with the latch in its unlockingposition;

FIG. 3 is a similar sectional view showing the latch in its lockingposition;

FIG. 4 is a fractional front elevation of the attachment plate with thelatch, and

FIG. 5 is an elevational view of a locking plate.

Referring to FIGS. 1 and 2, the automatic door lock proposed by thepresent invention is secured in a known manner to an attachment plate 1and accommodated within a lock case 2 which has a mounting plate 3supporting a damping cylinder 4. The cylinder 4 is retained in itsposition by fitting edges 7.

The damping cylinder 4 is filled with oil and also accommodates anaxially movable piston 5 and a spring 6 which serves as an energystorage means. The spring 6 helically surrounds a piston rod 8 which isintegral with the piston 5. The free end of the piston rod 8, whichprojects out of the damping cylinder, mounts a frameshaped slidingmember 9 movable in a straight guide.

The lock case 2 supports a pivot 10 passing through guide slots 11 inthe side walls of the sliding member 9 thereby to ensure rectilinearmovement of this latter. Within the frame-shaped sliding member 9, aneccentric disc 12 is rigidly mounted on the pivot 10. An abutment plate13 is inserted in the sliding member 9 and preferably covered by a thinresilient contact member 14, which arrangement is to reduce the frictionwithin the sliding member.

The pivot also carries a latch 15, the shape of which is shownparticularly in FIG. 4. Preferably, the latch 15 is mounted on apolygonal extension 16 of the pivot 10. Pivot 10, eccentric disc 12 andlatch 15 thus can be rotated in common only.

The piston 5 is sealed off against the bore of the damping cylinder 4 bymeans of a piston ring 17 and a piston packing 18. A plug 19 closing theopen end of the cylinder 4 and having a central passage for the pistonrod 8 is sealed by a plurality of packing inserts 20. Internally, thepiston 5 is provided with channels 21 having throttling openings.

FIG. 5 shows the shape of a locking plate 23 to be secured to the jamblinings of a door by means of screws.

FIGS. 2 and 4 show the latch 15 in its unlocking position. In thisposition, the sliding member 9 is lifted together with the piston 5 bythe action of the eccentric disc 12. The eccentric disc 12 has beenpivoted into a position beyond its dead center, which is conditioned bya fiat edge portion 24 of the periphery of the eccentric disc 12, sothat the latch 15 is arrested in its unlocking position.

When the door is being closed, the latch 15 will strike against a nose25 of the locking plate 26, whereby the eccentric disc 12 is turned backfrom its beyond-dead center position so that the sliding member 9, underthe action of the spring 6, can pivot the eccentric disc 12 and thus thelatch 15 into the locking position of the latter, which is designated byreference numberal 15 in FIGS. 3 and 4. Simultaneously, the closingmovement of the door is damped by the action of the piston 5.

The latch 15 and the locking plate 23, which, of course, may have anydesired shape, are preferably made of wear-resistant plastic or bronze.The same also applies to the eccentric disc 12.

It is self-evident that instead of using the pivot 1% as a guide pinwithin the slots 11, any other guide, for example of rail shape, canalso be used.

To reduce wear, the eccentric disc 12 used is preferably positivelycoacting with the sliding member 9, which will be the case with acircular disc or an arched triangw lar disc provided with a flattenedportion on the periphery such as the flat edge portion 24, to obtain abeyonddcad center position.

Instead of the cam drive comprising the sliding member 9 and theeccentric disc 12, as described with refer ence to the illustratedembodiment, also difierent cam drives can be used, as a matter ofcourse. For example, the sliding member 9 may have any other shape andinstead of the eccentric disc 12 a cam may be used.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claim rather than by the foregoing description and all changeswhich come within the meaning and range of equivalency of the claim aretherefore intended to be embraced therein.

I claim:

An automatic door lock comprising means defining a chamber, a pistonmounted for rectilinear reciprocal movement in said chamber means, apiston rod coupled to said piston and having an end portion projectingoutwardly of said chamber means, an eccentric, means coupling theeccentric to the piston rod end portion, said eccentric being mountedfor movement between overcenter and non-overcentcr positions wherebysaid piston rod is moved in at least one direction, said coupling meansincluding a member carried by said piston rod end portion, said memberhaving a portion in underlying relationship to said eccentric, pivotmeans coupled to said eccentric and mounting said eccentric for swingingmovement about a fixed axis, a latch carried by said pivot means wherebymovement imparted to said latch in a iirst direction causes saideccentric to move to the overcenter position thereof while movementimparted to said latch in a second opposite direction causes saideccentric to move to the undercenter position thereof, means forreducing the frictional contact between said member and said eccentric,and said reducing means being defined by resilient means underlying saideccentric.

References Cited by the Examiner UNITED STATES PATENTS 1,120,544 12/1914 R'osentreter 1655 2,588,010 3/1952 Kennon 16-55 2,851,296 9/1958Guyaz 292-78 2,946,613 7/ 1960 Roethel 16-2 FOREIGN PATENTS 1,130,325 5/19 62 Germany.

337,998 11/ 1930 Great Britain.

745,271 2/1956 Great Britain.

304,335 3/ 1955 Switzerland.

' EDWARD c. ALLEN, Primary Examiner.

